U.S. patent application number 11/163085 was filed with the patent office on 2006-04-06 for appliance and method for surface treatment of a board shaped material and floorboard.
This patent application is currently assigned to VALINGE ALUMINIUM AB. Invention is credited to Niclas Hakansson, Darko Pervan, Jan Peterson.
Application Number | 20060073320 11/163085 |
Document ID | / |
Family ID | 33434196 |
Filed Date | 2006-04-06 |
United States Patent
Application |
20060073320 |
Kind Code |
A1 |
Pervan; Darko ; et
al. |
April 6, 2006 |
Appliance And Method For Surface Treatment Of A Board Shaped
Material And Floorboard
Abstract
A device for coating surface portions of a board material with a
liquid material. The device includes a wheel which transfers the
coating material and compressed air which positions the coating
material. A method for surface coating and a floorboard with a
finished surface portion.
Inventors: |
Pervan; Darko; (Viken,
SE) ; Peterson; Jan; (Lerberget, SE) ;
Hakansson; Niclas; (Helsingborg, SE) |
Correspondence
Address: |
BUCHANAN INGERSOLL PC;(INCLUDING BURNS, DOANE, SWECKER & MATHIS)
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
VALINGE ALUMINIUM AB
***
Viken
SE
|
Family ID: |
33434196 |
Appl. No.: |
11/163085 |
Filed: |
October 4, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60615963 |
Oct 6, 2004 |
|
|
|
Current U.S.
Class: |
428/292.4 ;
118/63; 427/290; 427/325; 427/348 |
Current CPC
Class: |
B05C 1/08 20130101; B05D
3/12 20130101; B05D 7/06 20130101; B05D 1/28 20130101; Y10T
428/249925 20150401; E04F 15/02 20130101; E04F 15/02033 20130101;
B27N 7/00 20130101; E04F 15/04 20130101; E04F 2201/0153 20130101;
B05D 3/042 20130101; B44C 5/0469 20130101; B05C 11/06 20130101;
E04F 13/08 20130101; B05C 11/1039 20130101; B05C 1/006 20130101;
B05C 1/0813 20130101 |
Class at
Publication: |
428/292.4 ;
427/290; 427/325; 427/348; 118/063 |
International
Class: |
B05D 3/00 20060101
B05D003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 5, 2004 |
SE |
0402419-6 |
Claims
1. A device for coating a liquid coating material on a surface
portion of a sheet-shaped blank comprising a core of wood or wood
fibers and a top layer, wherein the surface portion is machined
such that it lacks the top layer, said device comprising a wheel
and a compressed air nozzle, the wheel is arranged so as to
transfer the coating material to the surface portion by a rotary
motion, and the compressed air nozzle is arranged to apply air to
the top layer so as to move the coating material in a contactless
manner using an air flow.
2. The device as claimed in claim 1, wherein the surface portion is
an edge of the sheet-shaped blank, and a width of a portion of the
wheel transferring the coating material, is broader than a width of
the surface portion.
3. The device as claimed in claim 1, wherein the surface portion is
a groove in the sheet-shaped blank, and a width of a portion of the
wheel transferring the coating material is essentially equal or
slightly smaller than a width of the surface portion.
4. The device as claimed in claim 1, wherein the sheet-shaped
material is a floorboard with a mechanical locking system.
5. The device as claimed in claim 1, wherein the machined surface
portion touches an unmachined portion of the top layer and is
visible from a surface of the top layer when the sheet shaped blank
is mounted.
6. The device as claimed in claim 5, wherein the wheel transfers
the coating material to the machined surface portion and to at
least part of the unmachined surface of the top layer, the air from
the compressed air nozzle moving the coating material from the
unmachined surface of the top layer to the machined surface
portion.
7. The device as claimed in claim 2, wherein the top layer is a
laminate, and the core material is HDF.
8. The device as claimed in claim 2, wherein the top layer material
is plastic, linoleum or rubber, and the core material is HDF.
9. The device as claimed in claim 2, wherein the top layer material
is wood or wood veneer protected with one or more layers of oil or
varnish, and the core material is wood or wood fiber.
10. The device as claimed in claim 2, wherein the core material is
massive wood and the top layer is a protecting layer of oil or
varnish.
11. The device as claimed in claim 1, wherein the coating material
is a pigmented oil.
12. The device as claimed in claim 1, wherein the wheel has a
scraper which controls an amount of coating material on outer parts
of the wheel as the wheel rotates.
13. The device as claimed in claim 11, wherein the coating material
comprises pigments, a binder and a viscosity-reducing agent.
14. The device as claimed in claim 11, wherein the coating material
comprises organic pigments, vegetable alkyds and mineral oil.
15. The device as claimed in claim 14, wherein a largest percentage
share by weight of the coating material is mineral oil and a lowest
share is pigments.
16. The device as claimed in claim 1, further comprising a filter
container for receiving excess of coating material which is blown
away by the air flow.
17. A method for making a decorative surface portion on a
floorboard, said floorboard comprising a core of wood or wood fiber
and a top layer having an unmachined surface and a surface portion
which touches the unmachined surface of the top layer, the method
comprising: removing a portion of the top layer to form the surface
portion by machining, coating the surface portion and part of the
unmachined surface of the top layer with a liquid coating material,
and moving the coating material on the unmachined surface of the
top layer by air towards the surface portion.
18. The method as claimed in claim 17, wherein the top layer is
impregnated with thermosetting resins, and the core and the surface
portion are made of HDF.
19. The method as claimed in claim 17, wherein the coating material
comprises pigments, a binder and a viscosity-reducing agent.
20. The method as claimed in claim 19, wherein the coating material
comprises organic pigments, vegetable alkyds and mineral oil.
21. The method as claimed in claim 19, wherein a largest percentage
share by weight of the coating material is mineral oil and a lowest
share is pigments.
22. A method as claimed in claim 19, wherein a share of pigments is
5-20%.
23. A floorboard comprising a top layer of laminate, a core of HDF
and a machined surface portion of HDF, the surface portion is
machined such that it lacks the laminate and is visible from the
surface when the floorboard is mounted, and the surface portion is
impregnated with a pigmented oil.
24. The floorboard as claimed in claim 23, wherein essentially the
entire unmachined surface of the top layer closest to the surface
portion is free from pigmented oil.
25. The floorboard as claimed in claim 23, wherein the coating
material comprises pigments, a binder and a viscosity-reducing
agent.
26. The floorboard as claimed in claim 23, wherein the coating
material comprises organic pigments, vegetable alkyds and mineral
oil.
27. The floorboard as claimed in claim 23, wherein a largest
percentage share by weight of the coating material is mineral oil
and a lowest share is pigments.
28. The floorboard as claimed in claim 23, wherein the share of
pigments is 5-20%.
29. The floorboard as claimed in claim 23, wherein the surface
portion is a groove with a bottom substantially parallel to the
unmachined surface.
30. The floorboard as claimed in claim 23, wherein the surface
portion is a bevel.
31. The floorboard as claimed in claim 23, wherein the surface
portion comprises a rounded part.
32. The device as claimed in claim 1, wherein a width of the wheel
is always smaller than a width of the sheet.
33. The device as claimed in claim 7, wherein the top layer is a
sheet material impregnated with thermosetting resins.
34. The floorboard as claimed in claim 23, wherein the top layer is
a sheet material impregnated with thermosetting resins.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of U.S.
provisional application, Ser. No. 60/615,963, filed in the United
States on Oct. 6, 2004. The present application also claims the
priority of SE 0402419-6, which was filed in Sweden on Oct. 5,
2004. The contents of U.S. Ser. No. 60/615,963 and SE 0402419-6 are
incorporated herein by reference.
TECHNICAL FIELD
[0002] The invention relates generally to the technical field of
surface treatment of sheet-shaped blanks. The invention relates to
a device and a method for providing such surface treatment. The
invention also concerns a floorboard with a machined and finished
edge. The invention is particularly suited for use in floorboards
having mechanical locking systems. More specifically, the invention
relates above all to floors of the type that has a core and a
decorative top layer on the upper side of the core.
FIELD OF APPLICATION
[0003] The present invention is particularly suited for use in
floating floors, which are made of floorboards, which on the one
hand are joined mechanically with a joint system which is
integrated with the floorboard, i.e. factory mounted, and on the
other hand are made up of one or more preferably moisture-proof
upper layers of decorative laminate, preferably comprising sheet
material impregnated with thermosetting resins or other decorative
plastic material, an intermediate core of wood fiber-based material
or plastic material and preferably a lower balancing layer on the
rear side of the core. The following description of prior-art
techniques, problems of known systems as well as the objects and
features of the invention will therefore as non-limiting examples
be aimed mainly at this field of application, in particular,
laminate floors as well as varnished, oiled or painted wooden
floors. However, it should be emphasized that the invention can be
used for any boards, e.g., floor, wall, ceilings and wall panels,
and in any board materials and in floorboards with any joint
systems and also floorboards which are not floating but which are
glued or nailed to a subfloor. The invention can thus also be
applicable to, for instance, floors with one or more layers of
wood, plastic material, linoleum or combinations of different
materials, such as wood, plastic, cork, rubber or other materials
that are used as surface layers in floors. The invention can also
be applied to make decorative surface portions in homogeneous
materials, for instance homogeneous wooden floors, or to apply
moisture-repellent layers, friction-changing layers, glue or the
like to joint portions in sheet-shaped blanks.
BACKGROUND OF THE INVENTION
[0004] Laminate flooring usually consists of a core of a 6-9 mm
fiberboard, a 0.2-0.8 mm thick upper decorative top layer of
laminate, preferably comprising sheet material impregnated with
thermosetting resins and a 0.1-0.6 mm thick lower balancing layer
of laminate, plastic, paper or like material. The top layer
provides appearance and durability to the floorboards. The core
provides stability, and the balancing layer keeps the board plane
when the relative humidity (RH) varies during the year. The
floorboards are generally laid floating, i.e., without gluing, on
an existing subfloor.
[0005] Traditional hard floorboards in floating flooring of this
type are usually joined by means of glued tongue and groove
joints.
[0006] In addition to such traditional floors, floorboards have
recently been developed which do not require the use of glue and
instead are joined mechanically by means of so-called mechanical
joint systems. These systems comprise locking means, which lock the
boards horizontally and/or vertically. The mechanical joint systems
can be formed by machining of the core of the board. Alternatively,
parts of the locking system can be formed of a separate material,
which is integrated with the floorboard.
[0007] The main advantages of floating floors with mechanical joint
systems are that they can easily and quickly be laid with great
accuracy. A further advantage of the mechanical joint systems is
that the edge portions of the floorboards can be made of materials,
which need not have good gluing properties. The edge portions of
the floorboard can therefore be impregnated with, for instance,
wax, in order to improve the moisture properties.
[0008] The most common core material is fiberboard with high
density and good stability, usually called HDF--High Density
Fiberboard. Other wood fiberbased board materials, which could be
used are, e.g., MDF (Medium Density Fiberboard), chipboard, plywood
and OSB (Oriented Strand Board).
[0009] Laminate flooring and also many other floorings with a
decorative top layer of plastic, linoleum, wood, veneer, cork and
the like are made by the surface layer and the balancing layer
being applied to a core material. This application may take place
by gluing a previously manufactured decorative layer, for instance
when the fiberboard is provided with a decorative high pressure
laminate which is made in a separate operation where a plurality of
sheets of paper, impregnated with thermosetting resins, are
compressed under high pressure and at a high temperature. The
currently most common method when making laminate flooring,
however, is direct laminating which is based on a more modern
principle where both manufacture of the decorative laminate layer
and the fastening to the fiberboard take place in one and same
manufacturing step. Sheets of paper, impregnated with thermosetting
resins, are applied directly to the board and pressed together
under pressure and heat without any gluing.
[0010] Thick top layers of wood, for instance 1-4 mm, are usually
applied to a core consisting of wood blocks whose fiber direction
is perpendicular to the fiber direction of the surface layer.
Particle board, fiberboard or plywood is also used both when the
top layer is thick and also when the top layers are thin veneer
with a thickness of, for instance, 0.2-1.0 mm. The top layer of
wood is usually protected with one or more layers of oil or
varnish. In terms of manufacture it is advantageous if the surface
treatment takes place before machining of the edge.
[0011] In addition to these methods, a number of other methods are
used to provide the core with a surface layer. The core can be
painted and varnished. A decorative pattern can be printed on the
core surface, which is then, for instance, varnished with a wear
layer.
[0012] As a rule, the above methods result in a floor element in
the form of a large board, which is then sawn into, for instance,
some ten floor panels, which are then machined along the edges to
floorboards.
[0013] The machining of the edges is made in advanced milling
machines where the floor panel is positioned between one or more
chains and bands mounted in bearings, so that the floor panel can
be moved at a high speed and with great accuracy past a number a
milling motors, which are provided with diamond cutting tools or
metal cutting tools, which machine the edge of the floor panel.
[0014] In all these manufacturing methods, the floor panel usually
has a top layer when forming its edges by machining.
[0015] In recent years it has become more common to provide the
above-mentioned floor types with bevels or decorative grooves
preferably at the joint edges but also on the surface. These parts
are made after providing the floorboard with the decorative top
layer. After machining, the edge or decorative grooves must thus as
a rule be coated in different manners with, for instance, varnish,
paint or the like to achieve the necessary decorative properties
and to protect the visible and exposed parts from moisture, dirt
and wear. Parts of the joint system that are not visible from the
surface are often also coated with property-improving agents, for
instance wax, to improve the moisture-resistance and the laying
function.
KNOWN TECHNIQUES AND PROBLEMS THEREOF
[0016] In manufacture of a laminate floor with, for instance,
beveled edges or decorative grooves, which uncover the HDF core,
the uncovered edge is protected with, for instance, paint or
adhesive tape. Coating with paint usually occurs immediately after
machining of the edge using spray nozzles. It is difficult to
achieve efficient accuracy in relation to the surface of the top
layer of the floorboard and in relation to corner portions. It is
also difficult to achieve the required speeds. Existing equipments
are complicated, expensive and require much maintenance. The paint
covering the machined fibers is difficult to apply.
[0017] It is known that joint portions in wooden floors can be
coated by means of wheels or rolls, which apply a varnish layer to
an edge portion. The existing technique does not permit
sufficiently high speeds and above all accuracy is not
satisfactory. In many cases there will be undesirable residues of
varnish on the surface of the decorative top layer. If this is to
be avoided, there is a great risk that parts of the edge portions
will not be coated.
SUMMARY AND OBJECTS
[0018] A first object is to provide a device and a method for
coating a surface portion of sheet-shaped blanks, comprising a top
layer, with liquid material, which eliminates or reduces one or
more of the problems occurring in connection with the coating of
machined portions, above all edge portions, with great
accuracy.
[0019] A second object is to provide a floorboard with a decorative
top layer of laminate, comprising sheet material impregnated with
thermosetting resins, a core of a wood fiber based board,
preferably HDF and a machined visible joint edge consisting of the
core material. The machined edge, which thus consists of HDF
fibers, is impregnated with a liquid material that is
moisture-repellent, decorative and which besides is easier to apply
with great accuracy to the machined edge than are the coating
materials currently used.
[0020] The first object is achieved by the condition that the
coating of, for instance, a machined surface portion, which touches
an unmachined surface of a decorative top layer, should take place
by means of a wheel which transfers a liquid material to the
machined portion as well as to the unmachined surface of the top
layer. The device has a compressed air system that blows away
excessive rests of the liquid material from the surface of the
unmachined top layer and towards the machined surface portion.
[0021] By selecting suitable chemicals that do not adhere to the
unmachined surface of the top layer, especially if they are blown
away preferably immediately after coating, exact application can
occur where all machined surface portions closest to the unmachined
surface of the top layer have obtained a coating while at the same
time the unmachined surface of the top layer is free from the
applied chemicals. Laminate floors and many other floors often have
a surface, which is embossed to resemble a wood structure. In this
context, compressed air is more efficient than other known methods,
such as scraping off, to remove excess coating from the unmachined
surface.
[0022] The invention is particularly suited for use in the joint
edge portions of the floorboards, but one or more decorative
recessed grooves according to the invention can also be arranged in
any position between the joint edge portions of the
floorboards.
[0023] The floorboard can thus have a surface that consists of a
plurality of surface portions with decorative recessed grooves so
that a surface pattern is formed with a pattern corresponding to
tiles or elongate blocks or the like. Decorative surface portions
can be placed in any position on the surface of the floorboard and
they may have any extent or shape. They can be arranged on both
neighboring edges of two joined floorboards, but they can also be
arranged on one edge only. The decorative surface portion can, but
need not, have an extent covering the entire joint edge. The
decorative surface portion can be parallel to the joint edge but it
can also have a deviating shape, such as wave-shaped. Moreover it
does not need to have the same depth from the floor surface along
its entire extent or between two neighboring joint edges. Coating
of such variants can be effected by means of a wheel moving
vertically and/or horizontally as the board is moved past the
wheel. Decorative surface grooves in the surface of the board can
be coated by means of one or more wheels cooperating with one or
more compressed air nozzles that blow liquid excess material
towards the inner parts of the grooves.
[0024] The invention is particularly suited for use in floorboards
with mechanical joint systems which enable exact positioning of the
decorative surface portions of the floorboards relative to each
other and impregnation of joint edges to increase moisture
resistance.
[0025] According to a first aspect, a device is provided for
coating a surface portion of a sheet-shaped blank, comprising wood
or wood fibers and an unmachined top layer, with a liquid coating
material, said device comprising a wheel and a compressed air
nozzle. The wheel transfers the coating material to the surface
portion by a rotary motion, and the compressed air nozzle moves the
coating material in a contactless manner using an air flow.
[0026] According to a second aspect, a method is provided for
making a decorative edge on a floorboard, which has an unmachined
top layer and a machined surface portion in the edge. The surface
portion touches the unmachined surface of the top layer. The method
is characterized in that the surface portion and a part of the
unmachined surface of the top layer are coated with a liquid
coating material, and that the coating material on the surface is
then moved by air towards the machined surface portion.
[0027] The second object is achieved by a floorboard with a top
layer preferably comprising sheet material impregnated with
thermosetting resins a core of HDF and a machined edge of HDF which
is impregnated with a pigmented oil.
[0028] The uncovered core is impregnated after machining. Such
impregnation can take place with great accuracy if chemicals such
as different types of pigmented oil or pigmented wax are used.
Pigmented oil can be more suitable than wax since it does not have
to be melted before application. A characteristic feature of these
agents is that, in contrast to paint, they do not adhere to the
laminate surface and, when blown away from the surface of the top
layer and towards the machined surface portion with uncovered HDF
fibers, they penetrate quickly into the core of the floorboard.
Coating of a machined and beveled edge can take place quickly and
easily with great accuracy. The invention allows essentially the
entire laminate surface closest to the machined HDF edge to be free
from coating material while at the same time essentially the entire
HDF edge closest to the unmachined surface of the top layer is
impregnated.
[0029] The machined joint edge of HDF, which is visible when the
floorboards are joined can, of course, according to the invention
be machined to a number of varying shapes, such as rounded, beveled
in combination with different angles and radii. There may also be
recessed grooves essentially parallel to the surface.
[0030] Examples of embodiments of the invention will now be
described in more detail with reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIGS. 1a-b show a device for coating of board material.
[0032] FIGS. 2a-c show examples of coating of different surface
portions in a floor with a mechanical locking system.
[0033] FIGS. 3a-b show examples of coating with excess paint which
is sprayed away from the surface.
[0034] FIGS. 4a-c show coating by means of a plurality of
wheels.
[0035] FIGS. 5a-b show the embodiments according to FIGS. 2a and 2c
enlarged
DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0036] FIG. 1a shows a device according to an embodiment of the
invention, for coating a surface portion of sheet-shaped blank 1,
comprising a core 30 and a top layer 31, seen parallel to the
direction of travel of the board and FIG. 1b shows the device seen
perpendicular to the direction of travel of the board.
[0037] The sheet-shaped blank, for instance a floorboard 1 with a
top layer, is driven preferably through a machining line
horizontally in a direction D. In this embodiment, the floorboard 1
is oriented with an unmachined surface of the top layer 31
downwards. A machined surface portion 21, with the top layer
removed touches a wheel 2, which rotates in the direction of travel
R of the floorboard by means of a driving device 8. The wheel 2 is
rotated at the same peripheral speed as the speed of feeding of the
floorboard 1. The driving device 8 can rotate the wheel 2 at
different speeds, preferably between 10 and 200 m/min. A suitable
speed in connection with manufacture of floors is about 60-130
m/min. Using suitable chemicals, wheel diameters and materials
selected for the wheel 2, high speeds of up to 200 m/min can be
achieved without the coating material leaving the wheel. A suitable
wheel diameter is 120-200 mm. The wheel can be provided with a
freewheel so that any difference in speed between the board 1 and
the wheel 2 can be leveled out. The width of the wheel portion W,
which transfers the coating to the sheet-shaped blank, is
preferably smaller than the width of the sheet-shaped blank and
preferably in the range of 0.1-20 mm.
[0038] The wheel 2 is coated with a liquid material 6, such as
pigmented oil, varnish, paint, wax, glue and the like, in a
container 6 which preferably has a splash guard. The container can
be provided with an inlet, a discharge and an overflow tube 11 for
returning purposes.
[0039] In order to obtain the correct amount of coating material 6
on the wheel 2 there is preferably a scraper, which can be
controlled and locked by a micrometer. It should be possible to
adjust the wheel 2 with great accuracy relative to the board at an
angle as well as vertically and horizontally. This is suitably
performed by means of a turnable coordinate table 9. In FIG. 1 a
the wheel has an angle of about 10 degrees to the vertical plane.
Suitable angles for coating of beveled edges are 0-45 degrees. A
pump 7 can be used to continuously circulate the liquid coating
material 6 via a filter.
[0040] A photocell, a mechanical device or the like can be arranged
to activate a compressed air system with a nozzle 3 which blows
excessive coating material away from the unmachined surface of the
top layer 31 by an air flow A. Excessive material blown away by
compressed air can be caught in a container 10 provided with a
filter. The equipment can be provided with a PLC (Programmable
Control System) controlled automatic cleaning system. The device
allows coating with narrow tolerances. For instance, coating can be
performed with an accuracy of about 0.1 mm in relation to the
unmachined surface of the top layer. Optimum results are achieved
preferably if the floorboard is correctly positioned relative to
the wheel. This positioning can take place in the machining unit by
means of, for instance, chains and bands, or when the floorboard
leaves the machining unit by means of rules and pressing rollers.
To achieve great accuracy it is also preferable for the wheel 2 to
have essentially the same peripheral speed as the floorboard. It is
advantageous if the difference in speed is less than 10 m/min. For
a good result, it is not necessary for the wheel 2 to touch the
floorboard. The coating material is transferred to the floorboard
by surface tension.
[0041] FIG. 2a illustrates coating of a decorative groove 21 which
is substantially parallel to the surface of the top layer 31. In
this embodiment an air flows A is used to blow away excessive
coating material 6 from the surface of the top layer. FIG. 2b
illustrates a beveled edge 22. FIG. 2c illustrates coating of a
groove 23 which is located at a distance from the joint edge. In
this embodiment, two air flows A, A' can be used to blow away
excessive coating material 6 from the surface and towards the
groove.
[0042] FIGS. 3a and 3b illustrate how a beveled edge 22, without
the top layer, can be coated with liquid coating material, such as
varnish or pigmented oil. In this embodiment, the floorboard 1 has
an unmachined surface of a top layer 31 of, e.g., a laminate made
of sheet material impregnated with thermosetting resins or
varnished wood. The beveled edge is coated with coating material 6
which partly settles on the unmachined surface of the top layer 31.
Excessive coating material is blown away by compressed air A which
in this embodiment is blown parallel to the surface of the board
and moves the excess material towards the beveled edge 22. FIG. 3b
illustrates how the coating material 6 penetrates into the core 30
while at the same time the unmachined surface of the top layer 31
is free from coating material. Particularly good penetration can be
achieved if the core consists of wood fiber-based materials, such
as HDF, and if pigmented oils with a suitable viscosity are used,
which is adapted to the absorbing capacity of the HDF material.
[0043] FIGS. 5a and 5b illustrate an enlargement of the coating
according to the embodiments in FIG. 2a and 2c. The machined
surface portions are coated with coating material 6 which partly
settles on the unmachined surface of the top layer 31. The
excessive coating material on the surface of the top layer is
removed by an airflow. In the embodiment in FIG. 5a a grove in the
sheet-shaped blank is coated. The width of the wheel portion W,
which transfers coating material to the groove, is essentially
equal to the width of the groove P or slightly smaller. In the
embodiment in FIG. 5b an edge groove of the sheet-shaped blank is
coated. The width of the wheel W, which transfers coating material
to the edge groove, is preferably larger than the width of the edge
groove P.
[0044] If the edge of the wheel 2 has a suitable design and if the
amount of coating material 6 is well adjusted while at the same
time the amount, pressure and direction of the air are controlled
in a convenient manner, coating of the machined edge can be
performed with a better result than in using prior-art
technique.
[0045] FIGS. 4a-c illustrate how a beveled edge 22, without the top
layer and parts of the mechanical joint system, in this case the
tongue portion 32, can be coated, for instance, with a decorative
material on the beveled edge 22 and with an impregnating
moisture-repellent material on the tongue 32.
[0046] In this embodiment coating is performed using two wheels 2,
2'. The nozzle 3 has an outlet 24 directing the air substantially
parallel to the unmachined surface of the top layer 31 towards the
edge portion 22.
[0047] In this embodiment the second wheel 2' operates
substantially horizontally. The wheel can be coated with suitable
liquid substances in different ways using, for example, a spray
nozzle 25, with felt or suitable fiber materials containing the
coating material and the like. Alternatively the wheel 2' can
rotate in an associated vessel where the edges of the wheel
establish a seal against the edges of the vessel. A plurality of
wheels can be used. Various chemicals can be dried, hardened and
the like after coating according to prior art, using ultrasound, UV
light, heat etc.
[0048] The edge of the wheels 2 can be designed in various ways and
they can operate at optional angles from above and from below. All
parts of a mechanical joint system that can be machined by means of
large rotating tools can also be coated by means of wheels,
preferably, but not necessarily, in combination with compressed air
which facilitates positioning of the coating material.
[0049] Wheels are preferably made of metal but they can also wholly
or partly be made of plastic or rubber material. They can be heated
and they can contain ducts directing the coating material to
different contact surfaces between wheel and board. A plurality of
different coating materials can be applied in different steps in
succession. The wheels can also be used to shape, by pressure,
parts of the joint edge by compression of fibers. Vacuum can be
applied to the board in order to facilitate penetration. Liquid
materials can be applied which after hardening become elastic and
which then may constitute a joint seal that prevents moisture from
penetrating through the joint system. In this case the edges do not
have to be beveled.
[0050] The chemical composition of the coating material is
important for a good result. A suitable chemical for coating of
wood fiber-based board materials such as HDF, MDF, particle board,
plywood and the like is pigmented oil. Such a chemical quickly
penetrates into wood fiber-based materials, prevents penetration of
moisture into the machined surface portion while at the same time
different pigments make it possible to provide decorative edge
portions or grooves which may have the same shades of color as the
surface of the top layer, or shades deviating therefrom. Suitable
pigments are organic pigments which are used, inter alia, in the
graphical industry for printing on paper. These pigments function
well together with wood-based board materials. Vegetable alkyds can
be used as binder for the pigments. Mineral oil can be used to
reduce the viscosity so that the coating material quickly and
easily can penetrate into the wood fiber-based core while at the
same time it adheres to the wheel and does not leave the wheel at
high peripheral speeds. A suitable composition measured in parts by
weight is about 10-15% organic pigments, about 30-35% vegetable
alkyds and 50-55% mineral oil. These parts by weight can also be 5
percentage units greater or smaller than the range stated. Of
course, also other mixtures can be used within the scope of an
important basic principle that the coating material should contain
pigments, a binder and a viscosity-reducing agent. Another
important basic principle is that the mixing ratios should be such
that the greatest share is a viscosity-reducing agent while the
lowest share is pigments.
[0051] Further chemical substances can be added, such as other
types of oils, hardeners and like agents. These agents can also be
combined with additives that can improve the durability, such as
alumina. It goes without saying that these additives may affect the
above mixing ratios.
[0052] Pigmented oil is highly convenient for use in floorboards
with a surface layer of laminate. The oil does not penetrate into
the laminate surface and easily slides off the laminate surface
without leaving any visible traces when exposed to a suitable air
flow which directs the oil towards the machined joint edge where it
is easily and quickly absorbed by the HDF fibers.
[0053] The chemical composition described above also constitutes an
invention which can be used independently as a coating material,
for instance together with the prior-art methods of, for instance,
coating a surface in a joint edge preferably of a floorboard with a
wood fiber-based core or surface layer.
[0054] There may be a number of variants. The device can be used
for coating of previously treated surfaces and for changing the
surface properties in terms of appearance and function. Compressed
air can be used to position and move liquid coating material also
in the cases when coating is performed in some other manner than by
means of wheels, for instance by means of coating tools that coat
machined surfaces.
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